We report the observation of a paramagnetic contribution to the field cooled magnetization that develops below the superconducting transition temperature ${T}_{\mathrm{c}}$ in measurements performed on $\mathrm{Y}{\mathrm{Ba}}_{2}{\mathrm{Cu}}_{3}{\mathrm{O}}_{7}∕{\mathrm{La}}_{0.7}{\mathrm{Ca}}_{0.3}\mathrm{Mn}{\mathrm{O}}_{3}$ superlattices. The effect has been detected only for samples whose manganite layers are magnetically granular. We discuss our observation of this paramagnetic Meissner effect (Wohlleben effect) in terms of an inhomogeneous superconducting state at the interface with the magnetically granular manganite layers.
Tópico:
Magnetic and transport properties of perovskites and related materials